Pacesetter headers have a reputation for poor fitment and warping the flange resulting in exhaust leaks. I second a set of 5.13:1 ring and pinion sets. You'll be able to cruise at 60mph around 2200-2500rpm (which is perfect, since turning all that rubber alone is an added stress to the engine). If your truck is an automatic, get a manual.
If this can be done, look into finding a set of internals from an M5OD-R1 behind a 2.3L, 2.9L, or 3.0L truck as these have numerically higher gears in first, second, and third. Using the gearsets in these transmissions inside of a 4.0L based M5OD-R1 would give you a better start because of the lower first gear. I've never attemted this so I'm not entirely sure its possible.